linux-kernel - Re: [PATCH 0/6] Apple device properties

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Message-ID: <20160818203433.GP30909@codeblueprint.co.uk>
Date:   Thu, 18 Aug 2016 21:34:33 +0100
From:   Matt Fleming <matt@...eblueprint.co.uk>
To:     Lukas Wunner <lukas@...ner.de>
Cc:     linux-efi@...r.kernel.org, linux-kernel@...r.kernel.org,
        Andreas Noever <andreas.noever@...il.com>, x86@...nel.org,
        linux-acpi@...r.kernel.org
Subject: Re: [PATCH 0/6] Apple device properties

On Mon, 15 Aug, at 06:13:58PM, Lukas Wunner wrote:
> 
> But I would like to understand the "cannot jump through pointers at
> runtime" argument because the binary code looks to me like it should
> work on 32 bit. I guess I must be missing something obvious?

Ah no, I forgot that efi_boot_services_{32,64}_t doesn't contain
pointers - it contains u32/u64 objects. So yeah, your patch looks
fine.

It does trigger the following warnings when building for i386 though,

In file included from /dev/shm/mfleming/git/efi/drivers/firmware/efi/libstub/efi-stub-helper.c:14:0:
/dev/shm/mfleming/git/efi/drivers/firmware/efi/libstub/efi-stub-helper.c: In function ‘efi_get_memory_map’:
/dev/shm/mfleming/git/efi/arch/x86/include/asm/efi.h:205:3: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  ((efi_boot_services_64_t *)__efi_early()->boot_services)->f : \
   ^
/dev/shm/mfleming/git/efi/drivers/firmware/efi/libstub/efi-stub-helper.c:85:11: note: in expansion of macro ‘efi_call_early’
  status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
           ^
/dev/shm/mfleming/git/efi/arch/x86/include/asm/efi.h:206:3: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  ((efi_boot_services_32_t *)__efi_early()->boot_services)->f, \
   ^
/dev/shm/mfleming/git/efi/drivers/firmware/efi/libstub/efi-stub-helper.c:85:11: note: in expansion of macro ‘efi_call_early’
  status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
           ^
/dev/shm/mfleming/git/efi/arch/x86/include/asm/efi.h:205:3: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  ((efi_boot_services_64_t *)__efi_early()->boot_services)->f : \
   ^
/dev/shm/mfleming/git/efi/drivers/firmware/efi/libstub/efi-stub-helper.c:92:11: note: in expansion of macro ‘efi_call_early’
  status = efi_call_early(get_memory_map, map_size, m,
           ^
etc.